See, two possibilities exist.
1 There's no life after death:
You don't exist before or after your life.[1] You only perceive anything during your lifespan. Since you can't perceive anything before or after, your life is infinite for you. Because when it ends, there would be no you to notice.
Of course, such immortality ain't about prolonged lifespan, but it doesn't make it less cool (just maybe slightly off-topic here?).
2 There is life after death:
Then you won't die as such, period.
So the only problems left with are the inconveniences of aging.
I'd like to hear some critique on this, though; the idea seems too bulletproof to me, I don't like it.
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[1] It may be impossible to correctly imagine the condition when there is no yourself, mainly because there would be no yourself in this situation (some kind of catch-22 here).